Zooarchaeological research from central western Argentina has focused until recently on the relevance of large mammals, camelids in particular. t here exists relatively abundant ethnohistorical information that illustrates the importance of fish exploitation in the Guanacache lagoons during historical times. However, –with a few exceptions– the zooarchaeological record has been poorly explored in relation to this issue, even though a large number of fish remains are found on different areas of the plains. t his work deals with the data obtained from fish remains recovered at Altos de Melien II, sector I (Guanacache) and compares them with those from other archaeological assemblages recovered from nearby contexts. It aims to improve our knowledge about fish consumption in this area of north-eastern Mendoza, with special attention to potential formation processes involved in this kind of assemblages. t he ichthyoarchaeological record from AM II is dominated by the creole perch (Percichthys trucha), even though from specimens the patagonian pejerrey (Odontesthes hatcheri) have been also identified. Body part representation and other indicators have been analysed. It is suggested that the assemblage reflects primarily the waste products of subsistence exploitation.